A cloud generally has three deployment models: a public cloud (owned and operated by some enterprises, and providing quick access to a computing resource for another organization or an individual at a reasonable price), a private cloud (owned by a single enterprise or an individual), and a hybrid cloud (based on the private cloud, and combining a public cloud service at a strategic level). A virtual private cloud (VPC) is a dynamic configuration pool that is established based on shared computing resources provided by the public cloud. In the public cloud, all VPCs are isolated from each other, and a tenant may apply for various virtualized resources on demand in a VPC. The tenant may connect the VPC to a public network using a public network Internet Protocol (IP) address, or may connect the VPC to a conventional data center (DC) using a virtual private network (VPN).
Software-defined networking (SDN) is a network design concept that is put forward by the Clean Slate research group in Stanford University of the United States. A core idea is to separate a control plane from a data plane of a network device, centralize a network control right, and provide an open programmable interface. An SDN controller shields a difference between bottom-layer physical forwarding devices using a standard southbound interface, such as the well-known OPENFLOW protocol in order to implement resource virtualization, and provides a flexible northbound interface for an upper-layer service to perform network configuration and invoke a network resource on demand.
A data center established using an SDN technology and a virtualization technology is referred to as an SDDC, and a network of the data center is an SDDC network (SDDCN).
In a conventional data center, multiple equivalent servers constitute a server cluster that can provide a service in order to provide a user with an efficient, reliable, secure, and stable service. The server cluster uses a load balancing technology to equivalently share service traffic among all servers, and equally allocate requests to the servers in the server cluster in order to implement load balancing between all the servers in the server cluster. In a current SDDC, a load balancer (LBer) may be established in an SDDCN using an existing technology, and the LBer allocates a task to a serving node in the server cluster. However, a characteristic that in the SDDC, a tenant may flexibly configure an LBer (for example, implemented using a virtual machine) cluster and a service cluster in a VPC is not considered in this solution, causing inflexible serving node scheduling in the service cluster.